Jim,

IP Vicksburg was indeed terrible. I worked a recent project with the guy who died - he had just finished a GP recovery boiler rebuild last August in Palatka (prior to me "retiring" in December). Part of the issue is training - it just "ain't done no more"... The 3rd hand details I heard reflected highly on training and/or procedure.

The explosion had nothing to do with what this guy was doing, just an innocent contractor, fortunately for his family IP has deep pockets. The money IP will probably have to pay out would have bought a lot of training.

We have so many "authorities" that speak without knowing. Granted, a blog does not always bring out the most intelligent... but I was amazed at what I read regarding Vicksburg. I finally later kinda found out what happened, but I certainly initially knew what did not happen. One blogger insisted that it could have / must have been a smelt dissolving tank explosion... The news was clear that this was during a startup just after an outage. Where did the smelt come from? They burn out the bed just before the outage and start up on auxiliary fuel... besides, the top 5 floors blew up, not the basement. Their auxiliary fuel is natural gas... gas, with a specific gravity on 0.6 rises (that is why the smell is added).

Tomahawk was also bad. GP had a similar incident a couple of years ago - lifted the top off of an "empty" HD chest - I forget if it was H2S, or methane from microbe action on the stuff left in the "empty" chest. Both have happened, empty tanks are the most dangerous. Fortunately no one got hurt at GP (but could have).

Larry Wells
Atlanta, Georgia, USA

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Jim:

Your point about the quality of trade press articles is good. It is easy to send an e-mail to the editor and/or publisher and let them know when they have published something that is incorrect or misrepresented. One magazine where this happens routinely (and the editor publishes the correspondence) is Chemical & Engineering News - the weekly publication of the American Chemical Association.

Regards

Dene Taylor
New Hope, Pennsylvania, USA

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Jim,

This response is to your last two NIP IMPRESSIONs. In part, perhaps paper companies lack of innovation in the marketplace in part may be the result of a timidity in technical matters. That keeping the status quo in ideas and methods reduces the desire to innovate.

In my own experience I find that "peer reviews", though designed to enhance intellectual honesty, sometimes result in articles that provide the wrong impression. Though an article content is correct within the confines of the procedures used, there has not been sufficient scrutiny in terms of the more general domain of reality.

As specific examples I offer the following three. For decades pulp strength evaluations have been performed using plate dried handsheets. In the real world paper shrinks or is strained, making the handsheet data one point on a response surface. Torbjorn Walstrom (Predictions of Anisotropic Multiply Board Properties, 13th Fundamental Research Symposium, Cambridge, September 2005, 241-281) developed a tool for predicting manufactured board property strength by using a combination of two shrinkage levels of handsheets. The techniques could be applied to both paper and board and extended to properties like curl.

There have been articles that indicated low fiber MFA (microfibril angle) corresponded to higher strength and/or lower coefficient of moisture expansion (CME). These studies were done using never dried pulp and property measurements made on plate dried handsheets. The results of these studies could apply to MD properties of paper made from never dried pulp. On the other hand, properties of paper made from dried pulp or recycled fibers is another story. Anna Vianio et al (Observations on the microfibril angle of Finnish papermaking fibers, Appita 2007 397-403) concluded that pulp mills ... hardly need to worry about the MFA ... wood could play a role, but it seems that this becomes attenuated by the papermaking process (beating and drying). The study showed a marked increase in MFA of fibers of dried paper.

Many, if not most, published studies and these on curl only consider the effect of moisture change or the effect of fiber orientation. Of course, fiber orientation is very important. On the other hand, how often is the effect of things like internal strain (a term used by me to make it easier to understand dimensional changes) studied in terms its various effects. Copy paper curl is a good example where curl from moisture change does not explain it.

For more details of my opinions (on paper strength issues, for example), NIP IMPRESSIONS readers can go to the CELLULOSE COMMUNITY WEBSITE (http://pulpandpaper.ning.com/) where they can find a group named PHYSICAL PROPERTIES with a discussion called "Readings in Paper Physics". They may add a comment by becoming a group member.

Chuck Green
Webster, New York, USA

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